The PARI system is a package which is capable of doing formal
computations on recursive types at high speed; it is primarily
aimed at number theorists, but can be used by anybody whose primary
need is speed.

It is possible to use PARI in two different ways:

1) as a library, which can be called from an upper-level language
application (for instance written in C, C++, Pascal or Fortran);

2) as a sophisticated programmable calculator, named gp, which
contains most of the control instructions of a standard language
like C.
